The invention relates to a method to control a fuel pump for a direct injection system of a heat engine provided with a common rail comprising the steps of determining a minimum threshold based on the pressure in the common rail and on the speed of the heat engine, on the temperature of the high-pressure pump and on the inlet pressure of the high-pressure pump; calculating the objective fuel flow rate to be fed by the high-pressure pump to the common rail instant by instant in order to have the desired pressure value inside the common rail; comparing the objective fuel flow rate with the minimum threshold; and controlling the high-pressure pump based on the comparison between the objective fuel flow rate and the minimum threshold.